Intake Development
You guys have brought a tear to my eye!!! lol
01-30-2004, 03:45 PM
#27
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I have given this a little more thought. As with an exhaust system there is more than one way to tune. I have been focusing on Helmholtz tuning but the above diagram by Speed Racer does have potential as well. That tuning method is based on organ pipe resonance principles. Here's how it works:
If we look at an organ pipe, each pipe is tuned to a certain frquency based on its length and opening size. In our case the opening is the end. By adjusting the length we are adjusting the frequency to which it resonates. Changing the length changes the frequency. Even noticed how a trombone works? The above picture would be best described as a trombone intake rather than an adjustable trumpet.
I may have mentioned it above in this thread or maybe it was another but this is how I broadened the torque of my little Honda Civic. If I reposted this again from above I apologize. Just skip this paragraph then to the next one. That car needs tons of help. I had just installed a cold air intake tube similar to the ones the ricers use and noticed the car seemed down on power. This was verified by lower average gas mileage. Even though there was more flow power was off. Tuning must have been affected. I then made several different lengths based off of some 3" aluminum tubing I had lying around. I finally got the length way long to the point that the filter is in the passenger side front of the car down low. This audibly tuned the intake to a lower point and for obvious reasons but more importantly the car felt stronger on the low end. This once again was verifyed by better gas mileage. In fact I get better gas mileage than what the car was rated at from the factory. Top end power didn't seem any better but power was improved over the entire average powerband. This is where it counts.
What made me mention this again is a site posted in a different thread about a new Greddy intake. The web based translation devices suck so it would be very helpful if someone fluent in Japanese could translate it to verify what I think they are saying. Here's the web link from the other thread. Click on the link that says: "January 7 GRACER air INKUSU set MZ-M011B SE3P"
http://ocn.amikai.com/amiweb/browser...=yes&display=2
Hope that works.
If you look at their system, it is very long which would tune very low based on organ pipe resonance. From what I can make out from the very broken English in the translation is that Greddy found that just by removing the stock airbox and replacing it with just a filter, that power went down in some spots. However that by using a really long system, they not only gained a little average power down low but also gained all the way up to around 7000 rpm or so. Just by looking at their system I would guess that there is no top end gain to be had but then again average power is what makes you faster. Can someone go read the Japanese version and verify this? If this is true then it is the same thing that happened to me on my little Civic.
By designing a system that does this in conjuncion with a sliding trombone stlye pipe, the top end could also get a gain. The Helmholtz box would still be a good idea though. Both have their advantages and disadvantages. It would be nice to see development of each system and the comparisons between them.
If we look at an organ pipe, each pipe is tuned to a certain frquency based on its length and opening size. In our case the opening is the end. By adjusting the length we are adjusting the frequency to which it resonates. Changing the length changes the frequency. Even noticed how a trombone works? The above picture would be best described as a trombone intake rather than an adjustable trumpet.
I may have mentioned it above in this thread or maybe it was another but this is how I broadened the torque of my little Honda Civic. If I reposted this again from above I apologize. Just skip this paragraph then to the next one. That car needs tons of help. I had just installed a cold air intake tube similar to the ones the ricers use and noticed the car seemed down on power. This was verified by lower average gas mileage. Even though there was more flow power was off. Tuning must have been affected. I then made several different lengths based off of some 3" aluminum tubing I had lying around. I finally got the length way long to the point that the filter is in the passenger side front of the car down low. This audibly tuned the intake to a lower point and for obvious reasons but more importantly the car felt stronger on the low end. This once again was verifyed by better gas mileage. In fact I get better gas mileage than what the car was rated at from the factory. Top end power didn't seem any better but power was improved over the entire average powerband. This is where it counts.
What made me mention this again is a site posted in a different thread about a new Greddy intake. The web based translation devices suck so it would be very helpful if someone fluent in Japanese could translate it to verify what I think they are saying. Here's the web link from the other thread. Click on the link that says: "January 7 GRACER air INKUSU set MZ-M011B SE3P"
http://ocn.amikai.com/amiweb/browser...=yes&display=2
Hope that works.
If you look at their system, it is very long which would tune very low based on organ pipe resonance. From what I can make out from the very broken English in the translation is that Greddy found that just by removing the stock airbox and replacing it with just a filter, that power went down in some spots. However that by using a really long system, they not only gained a little average power down low but also gained all the way up to around 7000 rpm or so. Just by looking at their system I would guess that there is no top end gain to be had but then again average power is what makes you faster. Can someone go read the Japanese version and verify this? If this is true then it is the same thing that happened to me on my little Civic.
By designing a system that does this in conjuncion with a sliding trombone stlye pipe, the top end could also get a gain. The Helmholtz box would still be a good idea though. Both have their advantages and disadvantages. It would be nice to see development of each system and the comparisons between them.
02-01-2004, 12:07 PM
#28
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Rotarygod... ask and ye shall receive. I was only going to post a summary, but... it turned into a line by line translation. Merry Christmas.
The Sequential Dynamic Air Intake System (S-DAIS), which uses the engine intake pulses, has been introduced in the 13B-MSP. Simply removing the stock air cleaner box and only installing a open air cleaner has the opposite effect, a drop in power. Mid-range rpm power loss occurs.
The results of considering pipe diameter and length and repeatedly testing is a layout where the Air Inksu main body is put in the passenger side inner fender.
Using Air Inksu and a 80ö diameter pipe, intake resistance is reduced, and due to the long intake pipe length a dynamic turbocharging effect is created. Mid to high rpm intake air volume has been increased. When compared to stock, the largest output change is at close to 7,000 rpm where power increases more than 7.4kw (10ps/8hp).
Efficiently inhaling fresh air and bringing out the engine's maximum performance, it appeals with a sense of the existence of the powerful rotary engine's unique intake sound.
Also, for protection against water when driving in rainy conditions, an aluminum shroud is attached.
The Sequential Dynamic Air Intake System (S-DAIS), which uses the engine intake pulses, has been introduced in the 13B-MSP. Simply removing the stock air cleaner box and only installing a open air cleaner has the opposite effect, a drop in power. Mid-range rpm power loss occurs.
The results of considering pipe diameter and length and repeatedly testing is a layout where the Air Inksu main body is put in the passenger side inner fender.
Using Air Inksu and a 80ö diameter pipe, intake resistance is reduced, and due to the long intake pipe length a dynamic turbocharging effect is created. Mid to high rpm intake air volume has been increased. When compared to stock, the largest output change is at close to 7,000 rpm where power increases more than 7.4kw (10ps/8hp).
Efficiently inhaling fresh air and bringing out the engine's maximum performance, it appeals with a sense of the existence of the powerful rotary engine's unique intake sound.
Also, for protection against water when driving in rainy conditions, an aluminum shroud is attached.
Last edited by Japan8; 02-01-2004 at 05:07 PM.
02-01-2004, 04:30 PM
#29
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So I was basically correct! Woohoo!!! I knew that the stock box did something useful and there is the proof. Less midrange power without the box. Proper tuning wins again!
I still feel that a better designed Helmholtz system has more inherent potential but a fixed pipe is easier to construct. Thanks Japan8!
I still feel that a better designed Helmholtz system has more inherent potential but a fixed pipe is easier to construct. Thanks Japan8!
02-01-2004, 05:11 PM
#30
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No problem at all... glad to be of service. Besides... more "good" info that is out there only benefits the whole community.
It does indeed seem that you have the right idea... resonance tuning of the intake is important with the Renesis engine. I hope that we can see some more products appear on the market that take this info account, and maybe even work a variable tuned system as you've suggested.
It does indeed seem that you have the right idea... resonance tuning of the intake is important with the Renesis engine. I hope that we can see some more products appear on the market that take this info account, and maybe even work a variable tuned system as you've suggested.
09-26-2006, 09:11 AM
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Interesting thread. We're looking into designing a variable intake manifold for racing only (5500 - 9000 rpm) essentially for cost reduction and simplification of engine management (we are going to build a seconf sport proto).
Continuously variable is not an option, but we'd look into something with vacuum actuated VDI and APV.
Continuously variable is not an option, but we'd look into something with vacuum actuated VDI and APV.
09-26-2006, 09:52 AM
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RG's idea on the intake is very interesting...
If I had the money... (gimme 2-3 months) I might be down with the idea...
But the whole process seems like a lot of work....
Relocation of the battery??? Simply that itself would cost some 200....
Well... actually... This whole idea seems a little over my head....
If I had the money... (gimme 2-3 months) I might be down with the idea...
But the whole process seems like a lot of work....
Relocation of the battery??? Simply that itself would cost some 200....
Well... actually... This whole idea seems a little over my head....
Last edited by Keef; 09-26-2006 at 09:59 AM.
09-26-2006, 11:46 AM
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^^ From what I read, it made sense. But then, I haven't much experience in Wankel intake manifold design.
I'd like to get rid of the VDI which adds a lot of complexity. Wonder how much power would be lost, and if it can be recovered by other improvements to the intake manifold.
What I'd really like to do, is to get a desktop design to go to the dyno with, and be able to test it different tubes lengths to see what works and what doesn't.
Fabrice
I'd like to get rid of the VDI which adds a lot of complexity. Wonder how much power would be lost, and if it can be recovered by other improvements to the intake manifold.
What I'd really like to do, is to get a desktop design to go to the dyno with, and be able to test it different tubes lengths to see what works and what doesn't.
Fabrice
Last edited by Rasputin; 09-26-2006 at 12:44 PM.
09-26-2006, 11:48 AM
#36
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The Renesis intake manifold is a work of art when it comes to design. If you want to improve it, take it off and smooth out the rough castings inside a bit but leave everything working. It isa fantastic system that would be very hard to improve anywhere without really hurting power in other areas.
09-26-2006, 11:53 AM
#37
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Well I went back and re-read what I posted a couple of years ago an while I still think the idea has merit, I'm not so sure that the amount of potential gain that it would give would be worth all the effort. It might make a few more horsepower if implemented properly but that's not much power to put so much effort into. Every little bit does help though. There are many other things to do to the car before getting to that.
09-26-2006, 12:59 PM
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Originally Posted by rotarygod
The Renesis intake manifold is a work of art when it comes to design. If you want to improve it, take it off and smooth out the rough castings inside a bit but leave everything working. It isa fantastic system that would be very hard to improve anywhere without really hurting power in other areas.
To summarise, we don't want to pay 2500 Eur for the alloy manifold + 600 Eur for the plastic one if we could design something (much) cheaper and simpler giving similar perf between 5500 and 9000 RPM. I'm also seriously considering moving from 6 to 4 bigger injectors with specific (return) fuel rails.
Fabrice
10-03-2006, 05:28 AM
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Originally Posted by rotarygod
If you are just looking for a race engine manifold then you could definitely do something much simpler at the expense of low end power.
Cheers,
Fabrice
10-03-2006, 11:51 AM
#41
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hmm dont know where i should put this now. but i said id put it here so here it is.
when Fred (RG) and i were discussing rx-8 intake design a few years ago at 7stock we talked about lengthing the primary. I think this would help in your situation. by removing most of thje S-DAIS functions you will lose some low end grunt. but you could make up some of that grunt with a longer primary. im not sure how much longer. it may have been discussed in this thread already somewhere i havent looked. i think the cross connect at 7250 should stay though for NA. that shortening of the intake path is what allows it to flow correctly for power above that rpm.
i had some star mazda tuning info around somewhere but it might be what Team sent you before.
when Fred (RG) and i were discussing rx-8 intake design a few years ago at 7stock we talked about lengthing the primary. I think this would help in your situation. by removing most of thje S-DAIS functions you will lose some low end grunt. but you could make up some of that grunt with a longer primary. im not sure how much longer. it may have been discussed in this thread already somewhere i havent looked. i think the cross connect at 7250 should stay though for NA. that shortening of the intake path is what allows it to flow correctly for power above that rpm.
i had some star mazda tuning info around somewhere but it might be what Team sent you before.
10-04-2006, 03:50 PM
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Last edited by Renesis_8; 09-11-2011 at 09:25 AM.
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